The team at FAR have discovered aphids in significant numbers in one of our barley trials at Chertsey
The barley is past the growth stage (GS) where we could consider yellow dwarf virus (YDV) to be a risk, so we won’t spray insecticide on this trial. Crops further advanced than GS32 are normally considered outside the risk period for YDV, and these barley plants are around GS49. The nearby wheat trials are on the cusp of the risk period (around GS31), but with the cold, wet weather that came through after we made the discovery, we have decided to forgo insecticide on the site as a whole this season.
Our advice to growers is that they should check their own cereal crops for aphids – ideally on a warm afternoon, at least 20-25m into the crop and on the lower leaves of plants. If you find significant numbers of aphids and your crop is before GS32, you may wish to consider an insecticide.
Spring sowings will be a different story. Vigilance is required if sowing untreated seed, and seed treated with insecticide only provides protection up until GS21. Crops will progress very quickly through the risk period of GS21-32, so keep checking for aphids through this time and apply an insecticide if needed. FAR is sowing spring cereal trials at Kowhai Farm, Lincoln, this year, and will be monitoring closely with sticky traps and regular inspections to inform our spray decisions as the season progresses.
Photo: the team at FAR have discovered aphids in significant numbers in one of our barley trials at Chertsey